Probability Worksheet for Class 8 Maths Olympiad

Maths Olympiad topic 24: Probability basics · Set 76 · 40 questions

How to solve it (Favourable over total): Probability = number of favourable outcomes ÷ total number of equally likely outcomes. List the outcomes: a dice has 6, two coins have 4 (HH, HT, TH, TT), three coins have 8, two dice have 36. Write the answer as a fraction in its lowest terms; a probability is never more than 1.

1. 1.A fair dice is rolled once. What is the probability of getting an odd number? (a) 1/3 (b) 2/3 (c) 1/6 (d) 1/2
2. 2.Two dice are rolled together. What is the probability that the two numbers add up to 9? (a) 4/11 (b) 1/11 (c) 1/9 (d) 5/36
3. 3.Two dice are rolled together. What is the probability that the two numbers add up to 3? (a) 2/11 (b) 1/18 (c) 1/12 (d) 1/11
4. 4.A bag has 9 red, 4 yellow and 8 green balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 4/21 (b) 1/3 (c) 17/21 (d) 6/7
5. 5.A fair dice is rolled once. What is the probability of getting a factor of 6? (a) 5/6 (b) 1/4 (c) 1/3 (d) 2/3
6. 6.Three coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 3/8 (b) 1/8 (c) 3/4 (d) 1/4
7. 7.Two coins are tossed together. What is the probability of getting exactly one head? (a) 2/3 (b) 1/2 (c) 1/4 (d) 1/3
8. 8.A fair dice is rolled once. What is the probability of getting a multiple of 3? (a) 1/2 (b) 1/6 (c) 1/3 (d) 2/3
9. 9.A bag has 4 yellow, 7 blue and 9 white balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/4 (b) 1/3 (c) 4/5 (d) 1/5
10. 10.A bag has 4 blue, 2 yellow and 5 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/6 (b) 1/3 (c) 6/11 (d) 5/11
11. 11.Two coins are tossed together. What is the probability of getting a head on every coin? (a) 1/3 (b) 1/4 (c) 1/2 (d) 3/4
12. 12.A fair dice is rolled once. What is the probability of getting a number less than 3? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
13. 13.Two coins are tossed together. What is the probability of getting at least one head and at least one tail? (a) 1/4 (b) 1/3 (c) 1/2 (d) 2/3
14. 14.Two dice are rolled together. What is the probability that the two numbers add up to 2? (a) 1/18 (b) 1/36 (c) 1/11 (d) 1/12
15. 15.Two dice are rolled together. What is the probability that the two numbers add up to 5? (a) 1/9 (b) 1/11 (c) 5/36 (d) 4/11
16. 16.A fair dice is rolled once. What is the probability of getting an even number? (a) 2/3 (b) 1/2 (c) 1/3 (d) 1/6
17. 17.Three coins are tossed together. What is the probability of getting exactly one head? (a) 3/8 (b) 3/5 (c) 1/4 (d) 5/8
18. 18.A bag has 4 white, 3 green and 5 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 7/12 (c) 2/3 (d) 5/12
19. 19.Two coins are tossed together. What is the probability of getting at least one head? (a) 1/3 (b) 1/2 (c) 3/4 (d) 1/4
20. 20.Two dice are rolled together. What is the probability that the two numbers add up to 10? (a) 1/11 (b) 1/9 (c) 1/12 (d) 3/11
21. 21.Three coins are tossed together. What is the probability of getting a head on every coin? (a) 1/7 (b) 1/4 (c) 7/8 (d) 1/8
22. 22.Two dice are rolled together. What is the probability that the two numbers add up to 7? (a) 7/36 (b) 1/11 (c) 6/11 (d) 1/6
23. 23.A bag has 7 red, 2 green and 8 blue balls. One ball is taken out without looking. What is the probability that it is not blue? (a) 9/17 (b) 1/3 (c) 10/17 (d) 8/17
24. 24.A bag has 8 green, 5 yellow and 9 white balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 9/11 (b) 5/22 (c) 17/22 (d) 1/3
25. 25.Two dice are rolled together. What is the probability that the two numbers add up to 12? (a) 1/36 (b) 1/12 (c) 1/18 (d) 1/11
26. 26.A fair dice is rolled once. What is the probability of getting a number less than 2? (a) 1/5 (b) 1/3 (c) 5/6 (d) 1/6
27. 27.Two dice are rolled together. What is the probability that the two numbers add up to 8? (a) 5/36 (b) 1/11 (c) 1/6 (d) 5/11
28. 28.A fair dice is rolled once. What is the probability of getting a number less than 4? (a) 1/6 (b) 2/3 (c) 1/3 (d) 1/2
29. 29.A bag has 6 red, 3 green and 8 yellow balls. One ball is taken out without looking. What is the probability that it is not yellow? (a) 1/3 (b) 8/17 (c) 9/17 (d) 10/17
30. 30.A fair dice is rolled once. What is the probability of getting a number greater than 2? (a) 5/6 (b) 1/4 (c) 1/3 (d) 2/3
31. 31.Two dice are rolled together. What is the probability that the two numbers add up to 4? (a) 1/11 (b) 3/11 (c) 1/9 (d) 1/12
32. 32.A bag has 3 blue, 2 green and 5 red balls. One ball is taken out without looking. What is the probability that it is not red? (a) 1/10 (b) 3/5 (c) 1/3 (d) 1/2
33. 33.A bag has 7 yellow, 8 blue and 3 white balls. One ball is taken out without looking. What is the probability that it is not white? (a) 1/3 (b) 1/6 (c) 8/9 (d) 5/6
34. 34.A bag has 8 yellow, 5 red and 5 green balls. One ball is taken out without looking. What is the probability that it is green? (a) 5/18 (b) 13/18 (c) 1/3 (d) 5/13
35. 35.A fair dice is rolled once. What is the probability of getting a prime number? (a) 1/6 (b) 1/2 (c) 2/3 (d) 1/3
36. 36.A bag has 9 white, 9 green and 2 red balls. One ball is taken out without looking. What is the probability that it is not white? (a) 9/20 (b) 11/20 (c) 3/5 (d) 1/3
37. 37.A bag has 9 yellow, 3 green and 6 blue balls. One ball is taken out without looking. What is the probability that it is yellow? (a) 1/18 (b) 5/9 (c) 1/2 (d) 1/3
38. 38.Two dice are rolled together. What is the probability that the two numbers add up to 11? (a) 1/18 (b) 1/11 (c) 1/12 (d) 2/11
39. 39.A bag has 6 green, 4 blue and 4 red balls. One ball is taken out without looking. What is the probability that it is green? (a) 3/4 (b) 3/7 (c) 4/7 (d) 1/3
40. 40.A bag has 4 green, 7 yellow and 9 red balls. One ball is taken out without looking. What is the probability that it is red? (a) 9/11 (b) 1/3 (c) 11/20 (d) 9/20

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